Approximately half of all Americans now live under some sort of sanctuary policy that shields illegal immigrants, according to a new study from the Federation for American Immigration Reform (FAIR).

FAIR calculated that 564 jurisdictions across the country have adopted policies that, to some degree, protect illegal aliens or obstruct efforts by the federal government to enforce U.S. immigration law.

That number is up more than 200 since President Trump took office and up more than 500 since former President Obama took office.

The Washington Times calculated that the jurisdictions on FAIR's list -- including entire states such as California and New York, along with major cities and counties -- make up 49 percent of the U.S. population.

On "Fox & Friends," FAIR President Dan Stein said this "explosion" of sanctuary policies is representative of a major division in the country.

"The Democratic Party is full-on against immigration enforcement, immigration control. And these sanctuary jurisdictions are a threat to public safety," Stein said.

He explained that it's extremely difficult for Immigration and Customs Enforcement to catch criminal illegal immigrants without cooperation from state and local authorities, which puts innocent Americans' lives in danger.

Stein said FAIR is fighting many of these sanctuary policies in court, because these jurisdictions are usurping the federal government's authority to decide who can stay in the U.S.

"States are trying to grab that authority, take it away, spend our taxpayer money on people with no right to be here, in-state tuition, all kinds of benefits," Stein said. "And then they turn around and say, 'Well, states don't have an obligation to help the federal government.' But [it] certainly seems like they have an obligation to assist illegal immigrants stay in the country."

Former U.S. attorney and Fox News contributor Andy McCarthy said it’s “ridiculous” that some Democrats are complaining about Attorney General William Barr’s review of the origins of the Russia investigation.